Indophenols and sulphur dyestuffs therefrom



$20 para to the -N 40 parts are by weight:

Patented July 25 1933 UNITED STATES PATENT OFFICE ERNESTOHAPMAN, OF MANCHESTER, ENGLAND, ASSIGNOR T IMPERIAL CHEMICAL INDUSTRIES LIMITED, A CORPORATION OF GREAT BRITAIN INDOPHENOLS AND SULPHUR DYElS'IUFES THEREFROM.

No Drawing. Application filed October 10, 1931, Serial No. 568,204, and. in Great Britain October 25, 1930.

This invention relates to the production of indophenols or leuco-indophenols and to the use thereof in the production of sulphur dyestuffs of novel shade and excellent fastness i properties.

According to the invention 1 oxidize together a phenolic amino compound such as p-amino-phenol and a tetralliyl-indoline of the general formula (wherein Ar represents an ortho-arylene radical devoid of substituent in the position group, B may be hydrogen or a hydrocarbon radical, and R, R-, R and R are aliphatic hydrocarbon radicals, the same as'or different from one another). I may also efiect interaction between the said tetralkylindolines and a 1 4=-nitrosophenol or a quinone chlorimide, to give a highly coloured indophenol. V

The so-obtained indophenols are readily converted by reduction processes. into; the

' corrcsponding leuco compounds.

According to a further feature of the invention, the new indophenols or their leuco compounds are treated with sulphurizing agents to. give sulphur dyestuffs of valuable green to blue shades and excellent :fastness properties, particularly fastness to chlorine. The" invention is illustrated, but not limited, by the following examples, in which the E trample 17.5 parts of 2 2 z 3 i 3-tetramethylindoline are dissolved by Warming in 80 parts of water containing 19 parts of hydrochloric acid of spe- 1345 cific gravity 1.1 8. The cooled solution is then mixed with one containing 14.6 parts of paminophenol hydrochloride in 120 parts water; The mixture is'cooled to 0 C. and 24.5 parts of hydrochloric acid of specific gravity 1.18 and. 600' parts of ice are added. With vigorousstirring an ice cold "solution of 20 partsof crystalline sodium dichromate in 120 parts water is added. The indophenol is produced almost immediately. It is reduced to the leuco compound directly by addition of 20 parts of zinc dust, sufficient hydrochloric ac d (35-40 parts) being added to keep the mixture feebly mineral acid in reactionto test papers." After stirring for some time the solution is heated to 90 C. and soda ash is added until the liquoris alkaline. The solution is filtered whilst still hot, and the solid matter is well washed, preferably with water containing a little sodium sulphide (to prevent oxidation) The entire liquor is cooled, and the free leuco indophenol is isolated by adding'24 parts of sodium bicarbonate and followed by saturation with carbon-dioxide. The leuco indophenol dissolves in dilute caustic'soda to give a deep red solution which turns blue on exposure to air. It has the following probable formula:

boiled under reflux with stirring for about 70 hours, after which the methylated spirit is removed by distillation, about 30 parts of Water being simultaneously run in.

The dyestufl? may be isolated by blowing air through the liquor or by acidification. It may bepurified, if desired, by dissolving in sodium sulphide solution and repreoipitation.

When applied in the usual way of sulphur dyestuffs it dyes cotton in greenish blue shades of good fastness to'light and. of outstanding chlorine fastness.

The product dyescotton in a somewhat greener shade when the sulphurization described above is carried out in the presence of copper or a salt thereof.

is filtered whilst hot.

E wample [I 9.45 parts of Bz-methyl-2: 2:3:3-tetramethylindoline (obtained by reduction of acetone-m-tolil, the position of the Bzmethyl group being unknown) are dissolved in 4-5 parts of warm water containing 4.6 parts sulphuric acid. This solution is cooled to 0 0., and added to an ice cold solution of 7 .3 parts of p-aminophenolhydrochloride in 60 parts of water. After the addition of a mixture of 6.45 parts of sulphuric acid, 7 parts of water and 300 parts of ice, an ice cold solution of 10 parts of sodium dichromate in 60 parts of water is run in quickly, followed. by 10 parts of zinc dust, with Vigorous stirring. Concentrated hydrochloric acid is added to keep the mixture just acid (about 20 parts being needed) and it is stirred for 40 minutes, The solution is then heated to 90 C. and soda ash 25-30 parts is added till'the solution is slightly alkaline to phenol phthalein. '30 parts of sodium sulphide crystals are added and themixture The leuco-indophenol is isolated in the manner described in Example 1. It has the following probable formula 7 CH3 Hogan -('1OH3 NC-CH3 Cm i a.

9 parts of the dry leuco indophenol so obtained are sulphurized in the manner described in Example 1.

The dyestufi" obtained dyes cotton in greenish blue shades.

Similar products are obtained when the isomeric I 2 2 3 37 pentamethylindoline (from acetone-o-tolil) is used.

Since many embodiments of this invention, differing widely in one or more re spects, may be made without departing from the spirit of my invention, it is to be understood that I do not limit myself to the foregoing examples or description except as indicated in the following claims:

I claim:

1. In the process of preparing indophenols, the step which comprises oxidizing a tetralkylindoline of the general formula:

RH! Riv R Ar O a it in which Ar represents an ortho-arylene radical devoid of substituent in the position para to the NR- group, R represents hydrogen or a hydrocarbon radical, and R,

in which Ar represents an ortho-arylene radical devoid of substituent in the position. para to the NR- group, R represents hydrogen or a hydrocarbon radical, and R, R, R, and R represent aliphatic hydrocarbon radicals which may be the same or different from one another, together with a compound of the group consisting of p-amino-phenol, 1:4 nitrosophenol, and quinone chloro-imides, and thereafter forming the leuco derivative by reducing the indophenol formed in the oxidation step.

3. In the process of preparing indophenols,

thesteps Which comprise oxidizing a tetralkylmdoline of the general formula:

RIII Riv /C A O in which Ar represents an ortho-arylene radical devoid of substituent in the position para to the 'NR- group, R represents hydrogen or a hydrocarbon radical, and RQR, R, and R" represent aliphatic hydrocarbon radicals which may be the same as or different from one another, together with a compound of the group consisting of p-amino-phenol, 1E4 nitrosophenol, and quinone chloroimides,-and thereafter sulphurizing the indophenol formed in the oxidation step.

4. In the process of preparing indophenols, the steps which comprise oxidizing a tetralkylindoline of the general formula:

ical devoid of substituent in the position para to the NR group, R represents hydrogen or a hydrocarbon radical, and R, R", R', and R" represent aliphatic hydrocarbon radicals which may be the'same as or different from one another,.together with a compound phenol which comprises oxidizing 2:2: 3:3 tetran'iethylindoline together with p-aminophenol, and thereafter reducing the indophe- 1101 thus formed.

R represent aliphatic hydrocarbon radicals.

11. As new products the tetra-alkyl indoline-indophenols which in the form'of their 14. As new products the sulphur dyes which are substantially identical with the products obtained by submitting the leuco indophenols described in claim 10 to a poly- 5 of the group consisting of p-amino-phenol, leuco derivatives have the probable formula 1:4 nitrosophenol, and quinone chlorogiven. in claim 9. p imides, reducing the indophenol formed in 12. As new products the tetra-alkyl-indothe oxidation step, and thereafter sulphurizline-indophenols which inthe form of their 1 ing the leuco indophenol formed in the reducleuco-derivatives have the probable formula I tion step. 7 given in claim 10. 75

5. The process of producing a new indo- 13. As new products the sulphur dyes phenol which comprises oxidizing 2:2: 3: 3 which are substantially identical with the tetramethylindoline together with p-aminoproducts obtained by submitting the leuco phenol. indophenols described in claim 9 to a poly- 6. The process of producing a new indosulphide fusion. 80

7. The process of producing a new indosulphide fusion.

phenol which comprises oxidizing 2: 2:3: 3 15. As a new product the tetra-alkyl-indotetramethylindoline together with p-aminollne-leuco-indophenol having the following phenol, and thereafter sulphurizing the indoprobable formula: phenol formed by the oxidation step. 0113 8. The process of producing a new indo- J;

phenol which comprises oxidizing 2: 2: 3:3 tetramethylindoline together with p-amino- N -c1n phenol, reducing the indophenol thus formed A igg g ig gf gg f i gg i ggigi fgz i y which dissolves in dilute caustic soda to 95 l 9' s new p g t6 yfi d01ine gave a deep red solution wh1ch turns blue on I I exposure 0 am lQUCi-iliCltiflJllGlltilSI havlng the following As a new product the y pro e Ormu Riv doline-leuco-indophenol having the followm ing probable formula: m0

HO-ONH- OR OHS N l R/I H DONE 1-OH3 l I R N- -oH3 40 in which R represents hydrogen or a hydro- CH3 E E3 106 carbon radical and. R, R", R', and R represent aliphatic hydrocarbon radicals.

10. As new products tetra-alkyl-indoline- 17 As a new product the sulphur dye which is substantially identical with the I p 0 product obtained by submitting the leuco ltuco-mdophenpls hax mg the followln indophenol described in claim 15 to a P y probable foimu a. R sulphide fusion. no

I 18. As a new product the 'sul hur dye W which is substantially identical i vith the i v L product obtained by submitting the leuco in- 1 dophenol described in claim 16 to a poly- R sulphide fusion.

in which R and R" represent hydrogen or hydrocarbon radicals, and R, R, R and ERNEST CHAPMAN. 

